JPH0556256B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a lined curved pipe, and more specifically, a lined elbow (hereinafter referred to as
This relates to the manufacturing method of LP joints.

[Conventional technology and its problems]

Generally, synthetic resin pipes have poor heat resistance, pressure resistance, and impact resistance, so to compensate for these drawbacks, they are constructed into composite pipes using steel pipes as reinforcement materials.

The manufacturing method for such composite pipes involves sufficiently surface-treating the inner surface of the steel pipe, applying adhesive to the inner surface of the steel pipe and the outer surface of the inner hard vinyl chloride pipe, and after these have dried, applying the inner hard vinyl chloride pipe to the inner surface. While degassing between the steel pipe and inner hard vinyl chloride pipe, heating and pressure lining is performed, and after cooling, the flange is turned back to form a finished product.

On the other hand, the principle of manufacturing methods for LP joints is the same as that for composite pipes, but various concrete proposals have been made (for example, Japanese Patent Publication No. 15462/1983, Miyazaki et al.; Application with,
(See page 600). However, currently being carried out,
The steps of a typical method for manufacturing LP joints by blow running are shown in Figure 6. In other words, in the process shown in Figure 6, if we explain the flanged elbow made of steel pipe, it is "pickled".
etc., and then apply adhesive to the inner surface. Next, it is "dried" in the same manner as in the method for manufacturing the composite pipe described above. On the other hand, for hard vinyl chloride pipes that have thermal expansion properties, the original pipe is "cut" and then "bended". Then, "adhesive is applied" to its outer surface, and "inserted" into the flanged steel pipe elbow at room temperature.

Next, these steel pipe flanged elbows and the bent hard vinyl chloride pipes installed therein are set in the housing as "pretreatment." The set is performed by fastening the flanges of a flanged steel pipe elbow with multiple bolts. Next, the flange of the oil pipe for circulating the heated oil is also set to match the flange of the steel pipe flanged elbow. After that, the oil is circulated inside the hard vinyl chloride pipe to heat the hard vinyl chloride pipe, and the outer periphery of the flanged steel pipe elbow is also heated with a burner or the like.
Dissolve the adhesive. Next, close the oil pipe provided on the outlet side of one flange,
Pressurizes the oil inside the hard PVC pipe. Therefore, the material for the LP joint is completed by applying so-called oil blowing and ``hydraulic lining.''
Next, as a "post-processing", a plurality of bolts on the flange of the steel pipe flanged elbow are removed from the housing, and the inner hard vinyl chloride pipe is "flipped" to complete the LP joint.

By the way, despite the recent demand for LP joints, the manufacturing method of LP joints using oil blowing is not suitable for bending hard PVC pipes,
Due to the process of drying the adhesive, etc., it is extremely time-consuming, has poor productivity (for example, 7 pieces/day), and increases the cost of the product.Therefore, there is a strong demand for a manufacturing method that can be mass-produced. .

[Means for solving problems]

Therefore, the present invention focuses on solving the problems of the conventional method of manufacturing LP joints using oil blowing, and through trial and error, the following invention was completed and is thus provided herein. That is, the gist is that in a method for manufacturing a curved pipe with a lining, in which a synthetic resin pipe is integrated into a curved metal pipe by fitting the synthetic resin pipe into the pipe via an adhesive, the synthetic resin pipe is straightened to a predetermined length. It is heated and softened in the form of a tube, and is fitted onto an arc-shaped pushing arm to form a bent pipe.Then, the pushing arm into which the formed synthetic resin bend pipe is fitted onto the outside is
After pushing the metal curved pipe into the synthetic resin bent pipe and closing both ends of the synthetic resin bent pipe, blow molding was performed using pressurized fluid to integrate the metal curved pipe and the synthetic resin bent pipe. A method of manufacturing a lined curved pipe is characterized by the following.

〔Example〕

The structure of the present invention will be explained in detail with reference to its working examples.

That is, the present example is as follows. For example, a flanged elbow with a nominal diameter of 80 to 250 mmφ is subjected to internal treatment such as ``pickling'', and then ``applying adhesive'' and ``heating'' the inner surface. On the other hand, hard vinyl chloride pipes are ``cut'' into a predetermined length, left in a straight tube state, and their outer surfaces are ``coated with adhesive'' and ``heated.'' Next, this cut original tube is fitted onto a plate-shaped arm whose long side is in the direction of the rotational axis and an arcuate arm centered on the rotational axis, and a "bend" is formed by the curvature of the arm. Then,
By rotating the arm to which the bent hard vinyl chloride pipe is fitted around the rotation axis, it is inserted into the flanged elbow which is held between the upper and lower halves of the mold. "Push",
Pressurized air is then introduced into the hard vinyl chloride tubing to form an "air lining" material. This is a manufacturing method for LP joints in which both ends of the hard vinyl chloride pipe fitted inside this material are cut off to complete the LP joint.

The equipment for using this manufacturing method is as follows:
Explain in detail.

FIG. 1 is a plan view of an apparatus for using the method of the present invention, showing a state in which the lower molds 4 and 17 are open, FIG. 2 is a side view as viewed from arrow A in FIG. 1, and FIG. A sectional view taken along line B-B in FIG. 2 is shown.

In these figures, the outline of this device is shown as a flanged elbow 1 with adhesive applied to the inner surface and flange 1a, and a flanged elbow 1 that is heated and softened, cut into a predetermined length, and with adhesive applied to the outer surface. It consists of a straight hard vinyl chloride pipe (hereinafter referred to as the original pipe) 2, and a first arm 7 for bending the original pipe 2 and pushing it into the flanged elbow 1. This is a device that manufactures LP joints.

To explain this in detail, 3 is the lower first clamp,
4 is a lower mold that is slidably attached to the lower first clamp 3; 5 is a first housing for placing the lower first clamp 3 and the lower mold 4; 6 is a first housing; A vertical axis provided under the housing 5 is located approximately at the center point of the arc of the flanged elbow 1. Reference numeral 7 denotes a first arm that pivots about the vertical axis 6, and is formed in an arc shape centered on the vertical axis 6 in plan view and in the shape of a long plate. A base 8 of the first arm 7 is formed in an elliptical shape, and an elliptical flange 9 and a short shaft 10 are connected to the base 8.

11 is a second arm, the tip of which is connected to the short axis 10 of the first arm 7 via a stand 12, and the base of the second arm 11 is connected to the vertical axis 6.
is fixed to.

An auxiliary stand 12a is attached to the stand 12, and these stands 12 and the auxiliary stand 12a
is erected on the substrate 13. The substrate 13 is fixed to the tip of the second arm 11.

The lower mold 4 is divided into two halves 4a and 4b, and two cylinders 14 and 15 are used to form the first mold.
They reciprocate on the housing 5 along the side surface of the lower first clamp 4 using rails 5a and 5b as guides to open and close each other.

Further, the second lower clamp 16 and the lower mold 17 shown in the first figure have the same structure as the first lower clamp 3 and the lower mold 4, and these 16,
17 is placed on the first housing 5.

The lower mold 12 is divided into two halves 17a and 17b, and the first
The lower second clamp 16 is reciprocated on the housing 5 using the rails 5a, 5a as guides to open and close each other. Note that the operations of the cylinders 18 and 19 are linked to the operations of the cylinders 14 and 15.

The lower first clamp 3, the lower mold 4, the lower second
Same structure as clamp 16 and lower mold 17,
Moreover, the lower molds 4 and 17 are in a closed state, and the integrated upper mold 20 is in the first housing 5.
It is installed on the top and can be raised and lowered using pillars 24, 25, and 26 as guides.

A plug body 21 having the same structure as the base portion 8, flange 9, and short shaft 10 of the first arm 7 is provided on the lower mold 17 side, and an air passage 22 is bored in this plug body 21. An air hose 23 is connected.

In addition, 27 is a pushing cylinder for pushing the master tube 2 into the first arm 7, 28 is a drive device composed of an air blower, etc., 29 is a base frame, and 30 is a second housing, which is fixed on the base frame 30. and the first housing 5 is assembled on top thereof. Reference numeral 31 denotes a frame body for suspending the drive device 28, 32 and 33 a bulging notch for bulging and attaching the raw tube 2 to the flange 1a of the flanged elbow 1, and 34 a short shaft. A notch 10 is fitted into it, and 35 is a notch into which the base part 8 is fitted.

The operation of this device is as follows. That is, the inner surface of the flanged elbow 1 and the flange 1
a) Apply adhesive to the outer surface and heat. This is suspended and placed on the lower first and second clamps 3 and 16 using a chain block or the like. At this time, the lower molds 4 and 17 are opened, and
The first arm 7 is retracted to the position shown in the first figure.

Therefore, the heated and softened raw tube 2 is transferred to the first cylinder 27, which is heated as necessary, by the pushing cylinder 27.
It is fitted onto the arm 7 and one end thereof is pushed into the base 8 to form a bent pipe. At this time, the other end of the original tube 2 slightly protrudes from the tip of the first arm 7. Next, when the drive device 28 is driven and the vertical shaft 6 is rotated, the first arm 7 is rotated via the second arm 11, and the original tube 2 is pushed into the flanged elbow 1. At that time, the base 8, flange 9 and short shaft 10 of the first arm are located between the open halves 4a, 4b of the lower mold 4.

On the other hand, on the side of the lower mold 17, the stopper 21 is pushed into the other protruding end of the original tube 2 using a cylinder (not shown).

Therefore, the cylinders 14, 15, 18, and 19 are operated, the lower molds 4 and 17 are closed, and the base 8 of the first arm 7, the flange 9, etc., and the stopper 21 are clamped, and in particular, the lower mold 4 is Both ends of the original tube 2 fitted onto the base 8 are held between the grooves of the elliptical notches 35 and 7. Next, lower the upper mold 20,
The mold is clamped like a normal air blow mold. Therefore, the flanged elbow 1 can be easily set.

Therefore, pressurized air is introduced into the air hose 23, and the inner tube 2 is expanded like a normal air blow, and is brought into close contact with the inner surface of the flanged elbow 1 and also with the flange 1a.

After that, the upper mold 20 is raised and the flanged elbow 1 is cooled with water, and then the flanged elbow 1 with the original pipe 2 integrated therein is taken out from the lower molds 4 and 17 (see Fig. 4), Cut along the protruding end flange 1a of the pipe 2 to complete the LP joint as shown in Figure 5.

Although this embodiment has been described using a flanged elbow made of a steel pipe, the present invention is not limited to this, and may be a bend made of a steel pipe, and both are collectively referred to as a curved pipe in this specification.

〔Effect of the invention〕

According to the present invention, when a synthetic resin tube softened by heating is fitted onto the arc-shaped pushing arm, a so-called bend tube is already formed there, so the step of forming the bend tube can be omitted. Additionally, the drying process after applying the adhesive and the heating process to melt the adhesive can be omitted, which dramatically improves the productivity of lined curved pipes and provides inexpensive lined curved pipes. can do.

[Brief explanation of drawings]

FIG. 1 is a plan view of an apparatus for using the manufacturing method of the present invention, FIG. 2 is a side view taken in the direction of arrow A in FIG. 1, and FIG. FIG. 4 is a perspective view of the appearance of the air lining material, FIG. 5 is a perspective view of the finished product, and FIG. 6 is a process diagram of a conventional example. 1... Elbow with flange, 2... Hard vinyl chloride pipe, 6... Vertical shaft, 7... First arm, 8... Base, 9... Flange, 21... Plug body, 23... Air hose .

Claims (1)

[Scope of Claims] 1. A method for manufacturing a lined curved pipe in which a synthetic resin pipe is fitted into a metal curved pipe via an adhesive and integrated, comprising: forming the synthetic resin pipe into a straight pipe of a predetermined length; The bent pipe is heated and softened by heating and softened, and then fitted onto the arc-shaped pushing arm to form a bend pipe.Then, the pushing arm into which the formed synthetic resin bend pipe is fitted is then heated and softened by the metal Push into the curved pipe, then
Production of a lined curved pipe characterized in that after both ends of the synthetic resin bent pipe are closed, blow molding is performed using pressurized fluid to integrate the metal curved pipe and the synthetic resin bent pipe. Method.